Halifax police are investigating an alleged sexual assault against a toddler in the city's north end.

Police say the incident happened around 7:30 p.m. Friday in the area of Wood Avenue when a young girl was outside playing with a group of children. A man asked her to come with him, then took her behind a building and touched her in a sexual manner.

Spokeswoman Const. Diane Woodworth said investigators are not releasing the child's age out of concerns for her privacy.

"It's a very small area (the neighbourhood) so we don't want people to be able to figure out who the victim is," said Woodworth.

She said the incident was reported to police by one of the child's parents just before 8 p.m. the same evening.

Woodworth said police have also talked with the victim and some of the children who were with her.

"It is very sensitive with young children. We have special investigators that are trained specifically to interview children and children services becomes involved ... and if the family wishes to proceed we will set up a joint interview."

The suspect is described only as a black man with a chubby nose and cheeks, wearing a bicycle helmet and riding a bike.

Woodworth said police are looking for anyone who matches the description. She said there have been no previous reports of anyone behaving in a similar manner around young children in the area.